Tumbling mill



April 1s, 1939.

o. E. ZAHN v A lTUMIBLING MILL,

' Filed July 14, 19:58 5 sheets-Sheet 1 /mm mZ Mm,

April 18,1939. w o. E. ZAHN I TUMBLI-NG MILL 5 sheets-sheet 2.y

Filed July 14, 1.938`

mvEN'roR Ya/faEZa/m/ April 18, 1939. o. E. ZAHN 2,154,883

TMBLING MILL -I Filed July 14, 1958 5 Sheets-Sheet s y JZ J4 ATTORNEY pril 18, 1939. O. E. ZAHN I 2,154,883

` -TUMBLING'MILL Filed Ju1y14, 1938 5 sheets-sheet 5y Il Il ll [l Il ll ll'll Il II LI II ll Il 1J Il ||\l\`l/lll ll ll Il Il ll ll ll Il* Il ll LII Il n INVENTOR v ggd ATTORNEY UNITED STATES PATENT OFFICE TUMIBLING MILL otto E. zahn, Mishawaka, Ind., assigner to American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application July 14, 1938, Serial No. 219,127

16 Claims. (Cl. 51-9) This invention relates to tumbling mills for have these main sprocket shafts radially disposed cleaning and smoothing castings, forgings and from the aforementioned axis of rotation of the the like. frame. Discs forming inner barrel heads may In cleaning, polishing, hardening or otherwise be suitably mounted in the master frame betreating metal articles such as castings, forgings tween consecutive main sprocket shafts for roand the like, the process may be carried out in tation; the axis of rotation of the shafts carrya tumbling mill in which the articles are placed ing these inner barrel head discs being also prefand subjected to the action of projected abrasive erably radially disposed with reference to the particles while the articles are being tumbled. axis of rotation of the frame and in the same when a single tumbling barrel is used it has horizontal plane as the axes of rotation of the 1'0 been the usual practice to charge the articles to main sprocket shafts. be treated into thebarrel when the supply of A conveyor may be trained over the sprockets projecting abrasive is shut oir. After charging and under the inner barrel heads on suitable the barrel, the abrasive may be projected on to guides Wherebi7 t0 ferm e plurality 0f 'Pee/kelle and against articles the-rein with suicient impact Means are DIOVded t0 Cause the Conveyor t0 15 to clean the articles such as castings while they travel linearly in a generally circumferential path are being tumbled. After they have been treated about the axis of rotation of the master frame the requisite length of time, the discharge of the thus to provide a tumbling action to objects in treated castings requires shutting off thev abrathe pockets- I sive supply while the tumbling barrel is being To form the outer end walls of the pockets, 20

unloaded and again loaded with more castings. rotate-ble diSCS may be mounted 0n Shafts suit- It is, therefore, desirable to avoid these shut ably journaled in frames, one for each pocket. downs and to maintain the abrasive projecting These discs may be adapted to form outer barmechanism in operation continuously whereby rel heads and the frames carrying them may be to do active work without the necessity of relapositioned opposite the inner barrel heads to form tively long shut downs incident to charging and with the conveyor and inner barrel heads a pluv discharging the tumbling barrel operating on the `rality of tumbling barrels. Provision is made to so-called batch system. raise or lower these frames thus to permit objects The present invention accomplishes the forein the barrels to be removed with facility; going desirable end by providing a frame or car- The master frame assembly thus generally de- 30 ier adapted to be rotated, the frame or carrier scribed may be mounted 0n Suitable Wheels rid- -serving to support a plurality of tumbling baring on Circular tracks and may be caused to rorels or pockets which are arranged to be brought tate bodily, step by step, ii desired, about a comin and out of the path of a stream oi" abrasive meh axis. A Suitable abrasive projecting meehprojected at blasting velocities. Provision is made anism may be mounted adjacent t0 the path of 35 to charge the barrels with objects to be treated travel O the tumbling barrels and positioned t0 at a predetermined position while objects in barthrow abrasive on to objects to be treated in the rels in the path of projected abrasive are receivtumbling barrels.

ing treatment. At the same time barrels con- As hereinbefore indicated, the master frame,

I taining objects which have been treated may be being designed for step by step rotation permits 40 discharged at another predetermined position. 0f Charging the barrels mOurlted thereon at a Consequently, the treatment which ordinarily, predetermined DOSitiOIl 0I' Station While simulalthough not always, consists in a cleaning or taneously articles are being cleaned or treated at blasting operation, may be substantially continanother StatlOIl Or Ste'tOIlS While, et the Same uous and the time incident to charging and distime cleaned or treated articles maybe discharged 45 charging is not utilized at the expense of shutat still another station. ting down the abrasive projecting mechanism. In addition to the apparatus described gen- According to one form of the invention, the erally in the foregoing, means are providedto co1- apparatus, which for convenience is herein relect abrasive which has been discharged into the ,.30 ferred to as a mill, may comprise a master frame tumbling barrels and return it to be recycled, if

generally circular in form adapted to be rotatably desired. driven on suitable supports about a vertical axis Although the novel features which are believed of rotation. A plurality of rotatable shafts with' to be characteristic of this invention will be parsprockets4 thereon may be mounted for rotation ticularly pointed out in the claims appended herein journals in the frame, it bein'g preferable to to, the invention itself, as to its objects and ad- 55 vantages. and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. 1 is a view in elevation of the tumbling mill;

Fig. 2 is a top plan view partly broken away;

Fig. 3 is a view on line 3-3 of Fig. 2;

Fig. 4 is a view on line 4-4 of Fig. 2;

Fig. 5 is a view of the lower side of a section of the conveyor; p

Fig. 6 is a view developed in a flat plane on line Sel of Fig. 2.

In the following description and in the claims,

various details will be identified by specic names for convenience, but they are intended to be as generic in their'application as the art will per-` mit. Like reference characters denote like parts inthe several figures of the drawings.

The master frame assembly represented generally by the reference character III comprises an inner wall II substantially circular in shape, supported on a circular channel member I2 which also may support vertically extending channels I3 held in spaced relation by members I 4 extending from said vertical channels to said inner walls II. 'I'he frame I0 is carried on wheels I6 journaled in circular channel members I2 and I8. A plurality of such wheels I6 ride on Va circular track I1 supported on I beams I 8 mounted on a suitable foundation I9. A sprocket chain 20 is mounted on a sprocket 2l extending around the frame III and driven by small sprocket wheel 22 mounted on a shaft 9 in turn driven by a belt 8 on a shaft 1 having a gear 6 engaging a gear 6 driven by an electric motor 4. Thus the frame may be caused to rotate on the circular track I1 about a vertical axis. -f

Mounted radially with respect to the axis of rotation of the frame Ill are a plurality of sprocket shafts 23 and 24. The inner ends of shafts 23 are mounted in suitable journals 26 in the inner wall II of the frame I9. 'I'he outer ends of the shafts 23 are mounted for rotation in journals 26 supported on cross members 21 fixed to the vertical channels I3. 'I'he sprocket shafts 24 are also mounted for rotation in the frame I9, the outer ends of shafts 24 being mounted in journals 28 supported in the same manner as journals 26. It will be noted, however, that the inner ends of shafts 24 differ from shafts 23 in that they extendinwardly and have aflxed thereto a worm wheel 29 which engages a worm 30 mounted to vrotate in a journal 3I in turn mounted in a bracket 32 carried on the inner wall II. Worm drive 30 is connected through a speed reducer 33 (see Fig. 4) and driven by sprocket wheel 34 and sprocket chain 36 driven by a motor 36.

'I'here are three such sprocket shafts 24 connected by worm gear mechanism as just described. Each worm shaft has a sprocket wheel 31 mounted thereon and a sprocket chain 38 engages them. Consequently when the motor 38 is driven, sprocket chain 36 drives sprocket wheel 34 and in turn through the speed reducer 33 the worm 30 is driven which also drives the three wheels 31, thus causing sprocket shafts 24 to rotate in their respective journals.

Sprocket shafts -23 and 24 each have keyed thereon a pair of sprocket wheels 39 and 40. Inner sprockets 39 are smaller in diameter than outer sprockets 40. Trained over these sprocket wheels 39 and 46 is an endless conveyor 4I to be described more in detail hereinafter.

Alternately with the sprocket shaft journals in the inner wall II are mounted journals 42. 'Ihese journals 42 carry short shafts 43 for rotation therein to which are fixed inner barrel head members 44. Mounted for rotation on frames 46 are outer barrel head members 46. The barrel heads 46 are fixed to short shafts 41 mounted for rotation in journals. which are in turn mounted on the frames 46. Also mounted on frames 46 are guide wheels 49 riding in channels I3. The frames 46, therefore, are movable vertically to bring the barrel heads 46 opposite barrel heads 44 and when the frames are lowered the barrel heads in turn are lowered away from a position opposite its complementary inner barrel head 44.

Y It will be observed that there is a frame 46 carrying an outer barrel head for each of the inner barrel heads 44. Each outer barrel head frame or carrier 46 has a guide wheel 69 which t rides in a track 6I mounted on the vertical casing wall 62 which encloses the master frame I3.

A semicircular. channel guide track segment 63 carried on brackets 64 mounted on the vertical channel members I3 of the master frame III is mounted adjacent each of the barrel head carrier frames 46. As will be described hereinafter in connection with the conveyory 4I, these guide segments are adapted to assist in causing the conveyor to form with the conveyor and barrelheads a plurality of radially disposed and, at the same time circumferentially arranged, tumbling barrels of generally truncated conical shape.

'I'he endless conveyor 4I comprises a series of radially disposed spaced apart bars 66 connected together at their inner ends by links 66'and 51 fixed to the bars. The links are connected by shafts carrying bearing wheels 69. Similar links 60 and 6I connect the outer ends of the bars. The shafts 62 connecting the links 69 and 6I, in

addition to carrying bearing wheels 62, also carry guide wheels 63 which ride in channel segments 63.'

The endless conveyor 4I is trained over the upper half of the sprockets 39 and 40 and under the inner barrel heads 44. 'I'he outer margin of the conveyor is trained to ride with the semicircular segments 63. By reason of the guide Wheels 63 riding in the channels and the inner margin of the conveyor being trained under the rotatable inner barrel heads 44, the conveyor is .adapted to form a plurality of radially disposed pockets (see Figs. 3 and 6). When the outer barrel head carrier 46 is raised in the position shown in Fig. 3 there is formed a tumbling barrel. vSix suchbarrels are shown but it is within the contemplation of the invention to have more or less.

It will now be apparent from the foregoing description that the conveyor may be driven linearly and in a generally circumferential path. Hence, objects in the pockets will be given a tumbling action. Bearing wheels riding in the sprocket grooves 64 of sprocket 40 on the driven sprocket shafts 24 will effect this movement. Furthermore the master frame vmay be caused to rotate about its vertical axis in a step by step movement. y The step by step movement may be effectuated by known means such as a time switch 3 in the electrical circuit connecting the motor 4. For convenience of description six centrifugal stations I to VI inclusive are indicated on the drawings (see Fig. 2).

Mounted over the pockets at stations III4 and IV on the top wall 65 of the casing designated generally by the reference character 66 are abrasive projecting mechanisms which may be of the throwing type. These. abrasive throwing wheels 61 may be mounted on a cantilever 68 pivoted on a support 69 mounted on the casing. A lug 10 extending from the lever 68 carries a guide wheel 1I riding in a channel 12 fixed to the master frame I0. This channel guide track at each tumbling barrel has a valley portion 13.` Hence it will be observed that as each pocket passes the abrasive projecting. stations III and IV the throwing wheel is lowered through openings 14 in the casing top wall 65. As the master frame I0 rotates the wheel may be lifted so as not to interfere with the movement of the frame. A guide slot 15 is provided in the casing which permits the shaft of the throwing wheel 61 to be lifted with the wheel. The abrasive throwing wheel may be driven by a motor 16 and belt 11.

There is provided in the casing 52 a charging port 18 and a discharging port 19. These are shown as being at stations I and VI respectively. The guide track 5| extending around the inside of the casing wall 52 is dipped -atstatlon VI. Consequently, when the frame is rotated the frames carrying the outer barrel heads 46 are lowered away from the tumbling pockets formed by the conveyor when at that station (see Fig. 46). As the frame I0 is further rotated the outer barrel head carrying frame 45 is raised as shown at station I (see Fig. 6) by reason of the guide wheel 50 travelling in the channel track 5I. The frame remains raised until it again reaches station VI, at the discharging port 19.

An abrasive collecting and recycling .mechanism is provided which comprises a collection trough 80 in the bottom of the bottom wall 8| of the casing. The collected abrasive may be raised through an elevation conduit 82 and returned to the abrasive charging chamber 83 from which the abrasive may be fed to the abrasive throwing wheels as desired through charging conduits 84 and 85.

The mill may be operated as follows: The various motors are caused to operate. While the frame I0 dwells by reason of its step by step rotation, castings are charged at charging port 18, station I. Meantime castings which have been charged to the tumbling barrels previously will be subjected to abrasive treatment at stations III and IV. When they have been given treatment for a predetermined length of time, the frame will rotate another step and the empty tumbling barrel will reach a position opposite the charging port 18, station I. Finally as barrels containing treated castings reach station VI, at the discharge port 19, the frame 45 will have been caused to move downwardly by reason of the dip (see Fig.4 in the guide track 5I. This moves the outer barrel head away from the end of the pocket leaving it open and the treated castings therein will be automatically discharged out of the discharging port 19 since the moving conveyor will cause them to be tumbling. The outer margin of the conveyor being lower results in the castings being forced out.

It will be observed that the mill described in the foregoing, may be operated continuously. As castings are being charged at one station, castings are being treated at another station or other stations and simultaneously treated castings are being discharged from the mill.

While certain novel features of the invention have been disclosed herein, and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art withoutde parting from the spirit of the invention.

What is claimed is:

1. In apparatus of the character described, a carrier mounted to rotate about an axis, an inner barrel head mounted on said carrier, an outer barrel head opposite said rst mentioned barrel head, a link conveyor adjacent said barrel heads and trained to form with said heads a tumbling barrel the axis of which is substantially radial to the axis of rotation of said carrier, and means to cause said tumbling barrel to move with said carrier in an arc about the axis of rotation of said carrier. K

2. In apparatus of the character described, a carrier mounted to rotate about an axis, a barrel head mounted on said carrier, a vertically movable frame opposite said rst mentioned barrel head, a barrel head mounted on said frame, a link conveyor adjacent said barrel heads and trained to form with said heads a tumbling barrel the ,axis of which is substantially radial to the axis of rotation of said carrier, means to rotate' said carrier to cause said tumbling barrel to move in an arc about the axis of rotation of said carr1er. A

3. In apparatus of the character described, a carrier mounted to rotate about an axis, an inner barrel head mounted on said carrier, an outer barrel head opposite said rst mentioned barrel head, an endless conveyor adjacent said barrel heads and trained to form with said heads a tumbling barrel the axis of which is substantially radial to the axis of rotation of said carrier, means to rotate said carrier to revolve said tumbling barrel in an orbit about the axis of rotation of said carrier and means to cause said conveyor to travel linearly and tumble articles in said barrel.

4. In apparatus of the character described, a carrier mountedto rotate about an axis, a r0- tatable barrel head mounted on said carrier, a vertically movable frame mounted 0n said carrier opposite said first mentioned barrel head, a rotatable barrel head mounted on said frame, an endless link conveyor adjacent said barrel heads and adapted to form with said heads a tumbling barrel, means to' rotate said carrier t0 cause said tumblingbarrel to travel inan orbit about the axis of rotation of said carrier, means to cause said conveyor to move linearly to tumble articles in said barrel and abrasive projecting mechanism mounted to rproject abrasive on to articles in said barrel.

5. In apparatus of -the character described, a frame mounted to rotate about a substantially vertical axis, means mounted on said frame carrying barrel ends, means mounting a conveyor, said conveyor being trained to form a plurality of tumbling barrels having their axes disposed substantially radially with reference to the axis of rotation of said frame, means to rotate said' frame about its axis of rotation, and means to cause said conveyor to travel linearly to tumble objects in said barrels.l

6. In apparatus of the character described, a master frame mounted to rotate about a substantially vertical axis, means mounted on said master frame carrying barrel ends. means mounting a conveyor, said conveyor being trained to travel in a generally circumferential path and to form a plurality of tumbling barrels having their axes disposed substantially radially with reference to the axis of rotation of said frame. means to rotate said frame about its axis of rotation, and means to cause said conveyor to .travel linearly and in said generally circumferential path to tumble objects in said barrels.

7. A tumbling mill which comprises a master frame mounted to rotate about a substantially vertical axis, means mounted on said frame carrying inner barrel heads, vertically movable means carrying outer barrel heads, means mounting a conveyor, said conveyor being trained t travel in a generally circumferential path and to iorm with said heads a plurality of tumbling barrels-having their axes disposed substantially radially with reference to the axis of rotation of said frame, means to rotate said frame about its axis of rotation, and means to cause said conveyor to travel linearly to tumble objects in said barrels.

8. A tumbling mill including a tumbling barrel comprising a section of an endless link conveyor trained to form a curvilinear pocket, means to rotate said conveyorlinearly to tumble articles in said pocket, a barrel head to close one end of said pocket, a second barrel head for the 0pposite end of said pocket, said second mentioned barrel head being movable to close said opposite end whereby to retain articles in said barrel during treatment thereof and to open said opposite end to automatically discharge articles from said pocket by the linear movement of said conveyor.

9. A tumbling mill comprising a rotatable frame, a plurality of tumbling barrels of substantially truncated conical shape radially disposed on said frame, the side walls of said barrels consisting of a continuous link conveyor movable linearly to provide a tumbling action to objects in said barrels, means for guiding said conveyor in a generally circumferential path and to form said side walls, means including driven sprockets to drive said conveyor linearly, means to rotate said frame whereby to cause said barrels to travel in4 an orbit about its axis of rotation, rotatable heads providing a closure for the inner ends of said barrels and heads movable toward and away from the outer ends of said barrels to provide a closure for said outer ends.

10. A tumbling mill comprising a generally .circular master frame mounted to rotate about a 'vertical axis, a continuous link conveyor, means to train said'conveyor to travel in a generally circumferential path about said axis and to form a plurality of pockets, inner barrel heads mounted for rotation in said frame to close the inner ends of said pockets, a plurality of frames mounted for vertical movement on said master frame, outer barrel heads mounted for rotation in said second mentioned frames to close the outer ends of said pockets, said heads and conveyor lforming a plurality of tumbling barrels rotatable in an orbit about the axis of rotation of said master frame, and abrasive projecting mechanism to project abrasive on to articles in said barrels in .their orbit of travel.

11. A tumbling mill comprising a generally circular casing, a master frame in said casing', a circular track mounted to carry said frame in said casing about a vertical axis, a continuous link conveyor, means including sprocket wheels and tracks to train said conveyor to travel in a generally circumferential path and to form a plurality of pockets, inner barrel heads mounted for rotation in said frame to close the inner ends of said pockets, a plurality of outer barrel heads carrying frames mounted for vertical movement, channels to guide said frames in their upward and downward movements, outer `barrel mounted for rotation in said second mentioned frames to close the outer ends of said pockets, a guide track on said casing to raise and lower said barrel head carrying frames, said heads and conveyor forming a plurality of. tumbling barrels when said barrel carrying frames are in their upper position, abrasive projecting mechanism to project abrasive on to articles in said barrels'.

12. A tumbling mill comprising a generally circular casing, a master frame in said casing, a circular track mounted to carry said frame in said casing about,a vertical axis, a continuous link conveyor, means including sprocket wheels and tracks to train said conveyor to travel in a generally circumferential path and to form a plurality of pockets, inner barrel heads mounted and downward movements, outer barrel heads mounted for rotation in said second mentioned frames to close the outer ends of said pockets, a guide track on said casing to raise and lower said barrel headv carrying frames, said heads and conveyor forming a plurality of tumbling barrels when said barrel carrying frames are in their upper position, abrasive projecting mechanism to project abrasive on to articles in said barrels, abrasive conveyor means to return abrasive projected into said barrels back to said projecting mechanism.

13. A tumbling mill comprising a generally circular master frame mounted to rotate about a vertical axis, a continuous link conveyor, means including sprocket wheels to train said conveyor to travel in a generally circumferential path and to form a plurality of pockets, inner barrel heads mounted for rotation in said frame to close the inner ends of said pockets, a plurality of frames mounted for vertical movement on said master frame, outer barrel heads mounted for rotation in said second mentioned frames to close the outer ends of said pockets, said heads and conveyor forming a plurality of tumbling barrels rotatable in an orbitabout the axis of rotation of said master frame, means to rotate said sprockets to cause said conveyor to travel linearly whereby to tumble articles in said barrelsv and abrasive projecting mechanism to project abrasive on to articles in said barrels in their orbit of travel.

14. A tumbling mill comprising casing,a generally circular master frame mounted to rotate in said casing about a vertical axis, a continuous link conveyor, means to train said conveyor to travel in a generally circumferential path and to form a plurality of pockets on said frame, inner barrel heads mounted for rotation in said frame to close the-inner ends of said pockets, a plurality of outer barrel head carrying frames mounted for vertical movement on said master frame within said casing, outer barrel heads mounted for rotation in said outer barrel head carrying frames to close the outer ends of said pockets, saidheadsand conveyor forming a plurality of tumbling barrels rotatable in an orbit about the axis of rotation of said master frame, a track mounted on said casing heads to raise said barrel head carrying frames during a part of the rotation of said master frame and to lower said barrel head carrying frame during another part of the rotation of said master frame and abrasive projecting mechanism to project abrasive on to articles in said barrels during a part of their orbit of travel.

15. A tumbling mill comprising a rotatable frame, an endless link conveyor, means to train said conveyor to form a plurality of radially disposed substantially truncated conical shaped pockets, a plurality of inner barrel heads rotatable on said frame and adapted to close the inner ends of said pockets, a plurality of outer barrel heads mounted for rotation in vertically movable carriers for the outer ends of said pockets, means to drive said conveyor linearly to tumble articles in said pockets, means to revolve said pockets in an orbit about the axis of rotation of said frame, means to move said carrier vertically to bring said outer barrel heads over the outer ends of said pockets during a part of their travel in said orbit and to remove said barrel heads from said outer ends during a part of their travel in said orbit,

16. A tumbling mill comprising a rotatable frame, an 4endless link conveyor, means lto train said conveyor to form a plurality of radially disposed substantially truncated conical shaped pockets, a plurality of inner barrel'heads rotatable on said frame and adapted to close the inner endsof said pockets, a plurality of outer barrel heads mounted for rotation in vertically movable carriers for the outer ends of said pockets, means to drive said conveyor linearly to tumble articles in said pockets, means to revolve said' OTTO E. ZAHN'. 

